Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 388 GPPTISSTQTQQALHGEKGQIKCFIRSTPPPDRIAWSWKETVLESGTSGRYTVETVTTEEGVISTLTMSNIVPADFQTIY 467
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2105458172 468 NCTAWNSFGSDTEIIRLK 485
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 305 PRMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGS-------GVVLSNENL--LTLKSVRQEDAGKYVCRAVVPrV 375
Cdd:pfam07679   1 PKFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQplrssdrFKVTYEGGTytLTISNVQPDDSGKYTCVATNS-A 79

                          90
                  ....*....|.
gi 2105458172 376 GAGEKEVSLTV 386
Cdd:pfam07679  80 GEAEASAELTV 90

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 224 LSVDPQPVLEGNLVKFHCSAKANPPVTlYRWAKGGSIIKEvSGD--TYEVTVDHS-FFTepvsCEVTNPLGSTnISRNVD 300
Cdd:pfam13895   4 LTPSPTVVTEGEPVTLTCSAPGNPPPS-YTWYKDGSAISS-SPNffTLSVSAEDSgTYT----CVARNGRGGK-VSNPVE 76

                  .
gi 2105458172 301 V 301
Cdd:pfam13895  77 L 77

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 388 GPPTISSTQTQQALHGEKGQIKCFIRSTPPPDRIAWSWKETVLESGTSGRYTVETVTTEEGVISTLTMSNIVPADFQTIY 467
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2105458172 468 NCTAWNSFGSDTEIIRLK 485
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 305 PRMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGS-------GVVLSNENL--LTLKSVRQEDAGKYVCRAVVPrV 375
Cdd:pfam07679   1 PKFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQplrssdrFKVTYEGGTytLTISNVQPDDSGKYTCVATNS-A 79

                          90
                  ....*....|.
gi 2105458172 376 GAGEKEVSLTV 386
Cdd:pfam07679  80 GEAEASAELTV 90

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172  311 PQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGSGVVLSNENL----------LTLKSVRQEDAGKYVCRAvVPRVGAGEK 380
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGRFsvsrsgststLTISNVTPEDSGTYTCAA-TNSSGSASS 79

                   ....*.
gi 2105458172  381 EVSLTV 386
Cdd:smart00410  80 GTTLTV 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172  22 QQPQDLVVVAGHPVTLPCTIPGYH--GVVLWIKDGLALgvgrDLSGYPRYTVigDHGSgehhLQIQRVELMDDAVFECQA 99
Cdd:cd05724     2 VEPSDTQVAVGEMAVLECSPPRGHpePTVSWRKDGQPL----NLDNERVRIV--DDGN----LLIAEARKSDEGTYKCVA 71

                          90
                  ....*....|....*.
gi 2105458172 100 --VQAAMRSRPARLTV 113
Cdd:cd05724    72 tnMVGERESRAARLSV 87

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 403 GEKGQIKCFIRSTPPPDrIAWSWKETVLESgtSGRYTVetvtTEEGVISTLTMSNIVPADfQTIYNCTAWNSFGSDTEII 482
Cdd:pfam07679  15 GESARFTCTVTGTPDPE-VSWFKDGQPLRS--SDRFKV----TYEGGTYTLTISNVQPDD-SGKYTCVATNSAGEAEASA 86

                  ...
gi 2105458172 483 RLK 485
Cdd:pfam07679  87 ELT 89

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172  20 FAQQPQDLVVVAGHPVTLPCTIPGY-HGVVLWIKDGLALGVGRdlsgypRYTVigDHGSGEHHLQIQRVELMDDAVFECQ 98
Cdd:pfam07679   3 FTQKPKDVEVQEGESARFTCTVTGTpDPEVSWFKDGQPLRSSD------RFKV--TYEGGTYTLTISNVQPDDSGKYTCV 74

                  ..
gi 2105458172  99 AV 100
Cdd:pfam07679  75 AT 76

Second immunoglobulin (Ig)-like domain of the nectin-like molecules Necl-1 - Necl-4; member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the nectin-like molecules Necl-1 (also known as cell adhesion molecule 3 or CADM3), Necl-2 (also known as CADM1), Necl-3 (also known as CADM2) and Necl-4 (also known as CADM4). These nectin-like molecules have similar domain structures to those of nectins. At least five nectin-like molecules have been identified (Necl-1 through Necl-5). These have an extracellular region containing three Ig-like domains, one transmembrane region, and one cytoplasmic region. The N-terminal Ig-like domain of the extracellular region belongs to the V-type subfamily of Ig domains, is essential to cell-cell adhesion, and plays a part in the interaction with the envelope glycoprotein D of various viruses. Necl-1 and Necl-2 have Ca(2+)-independent homophilic and heterophilic cell-cell adhesion activity. Necl-1 is specifically expressed in neural tissue and is important to the formation of synapses, axon bundles, and myelinated axons. Necl-2 is expressed in a wide variety of tissues, and is a putative tumour suppressor gene, which is downregulated in aggressive neuroblastoma. Necl-3 has been shown to accumulate in tissues of the central and peripheral nervous system, where it is expressed in ependymal cells and myelinated axons. It is observed at the interface between the axon shaft and the myelin sheath. Necl-4 is expressed on Schwann cells, and plays a key part in initiating peripheral nervous system (PNS) myelination. Necl-4 participates in cell-cell adhesion and is proposed to play a role in tumor suppression.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 229 QPVLEGNLVKFHCSAKANPPVTLYRWAKGGSIIKEVS-------GDTYEVT------VDHSFFTEPVSCEVTNP-LGSTN 294
Cdd:cd05761    14 SPVVEGDEITLTCTTSGSKPAADIRWFKNDKELKGVKevqesgaGKTFTVTstlrfrVDRDDDGVAVICRVDHEsLTSTP 93

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 protein (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1). These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development. Neph1 and 2 may mediate axonal guidance and synapse formation in certain areas of the CNS. In the kidney they participate in the formation of the slit diaphragm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 388 GPPTISSTQTQQALHGEKGQIKCFIRSTPPPDRIAWSWKETVLESGTSGRYTVETVTTEEGVISTLTMSNIVPADFQTIY 467
Cdd:cd05898     1 GPPIISSEQVQYAVRGERGKVKCFIGSTPPPDRIAWAWKENVLESGTLERYTVERTSTGSGVLSTLTINNIMEADFQTHY 80

                          90
                  ....*....|....*...
gi 2105458172 468 NCTAWNSFGSDTEIIRLK 485
Cdd:cd05898    81 NCTAWNSFGSGTAIIQLE 98

Fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (also known as Neph1), Kirrel2 (also known as Neph3), and Drosophila RST (also known as irregular chiasm C-roughest) protein. These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 388 GPPTISSTQTQQALHGEKGQIKCFIRSTPPPDRIAWSWKETVLESGTSGRYTVETVTTEEGVISTLTMSNIVPADFQTIY 467
Cdd:cd05758     1 GPPIITAEATQPAILGEKARLECLVFSSPPPDRIVWSWDEGFLESGSSGRFSVETFPTEPGVISVLHISGTQRSDFQTSF 80

                          90
                  ....*....|....*...
gi 2105458172 468 NCTAWNSFGSDTEIIRLK 485
Cdd:cd05758    81 NCSAWNRFGEGTAIVSLG 98

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2105458172 311 PQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRG------SGVVLSNENLLTLKSVRQEDAGKYVC 368
Cdd:cd20957     8 PPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGkplghsSRVQILSEDVLVIPSVKREDKGMYQC 71

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2105458172 305 PRMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRG---------SGVVLSNENLLTLKSVRQEDAGKYVCRA 370
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEATGSPPPTITWYKNGepissgstrSRSLSGSNSTLTISNVTRSDAGTYTCVA 76

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172   24 PQDLVVVAGHPVTLPCTIPGY-HGVVLWIKDGLALgvgrdLSGYPRYTVIGDHGSgeHHLQIQRVELMDDAVFECQAV-Q 101
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSpPPEVTWYKQGGKL-----LAESGRFSVSRSGST--STLTISNVTPEDSGTYTCAATnS 73

                           90
                   ....*....|..
gi 2105458172  102 AAMRSRPARLTV 113
Cdd:smart00410  74 SGSASSGTTLTV 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172  22 QQPQDLVVVAGHPVTLPCTIPGYH--GVVLWIKDGLALgvgrDLSGYPRYTVigDHGSgehhLQIQRVELMDDAVFECQA 99
Cdd:cd05724     2 VEPSDTQVAVGEMAVLECSPPRGHpePTVSWRKDGQPL----NLDNERVRIV--DDGN----LLIAEARKSDEGTYKCVA 71

                          90
                  ....*....|....*.
gi 2105458172 100 --VQAAMRSRPARLTV 113
Cdd:cd05724    72 tnMVGERESRAARLSV 87

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 310 EPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGSGVVLSNENLLTL-------KSVRQEDAGKYVCravVPRVGAGEKEV 382
Cdd:cd20952     5 GPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLengslqiKGAEKSDTGEYTC---VALNLSGEATW 81

                  ....
gi 2105458172 383 SLTV 386
Cdd:cd20952    82 SAVL 85

CD80-like C2-set immunoglobulin domain; These domains belong to the immunoglobulin superfamily.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2105458172 125 GPVVSLRAGDP-LNLTCHANNAKPAASIIWIRNGEVLNGAMYSKTLLRDGRRESTVSTLHLSPSNIETGQHIICKASN 201
Cdd:pfam08205   5 PPASLLEGEGPeVVATCSSAGGKPAPRITWYLDGKPLEAAETSSEQDPESGLVTVTSELKLVPSRSDHGQSLTCQVSY 82

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 403 GEKGQIKCFIRSTPPPDrIAWSWKETVLESgtSGRYTVetvtTEEGVISTLTMSNIVPADfQTIYNCTAWNSFGSDTEII 482
Cdd:pfam07679  15 GESARFTCTVTGTPDPE-VSWFKDGQPLRS--SDRFKV----TYEGGTYTLTISNVQPDD-SGKYTCVATNSAGEAEASA 86

                  ...
gi 2105458172 483 RLK 485
Cdd:pfam07679  87 ELT 89

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2105458172 310 EPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGSGVVL--------------SNENLLTLKSVRQEDAGKYVCRAV 371
Cdd:cd05726     5 KPRDQVVALGRTVTFQCETKGNPQPAIFWQKEGSQNLLfpyqppqpssrfsvSPTGDLTITNVQRSDVGYYICQAL 80

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2105458172 310 EPQSLQVDLGSDAVFNC-AWTGNPSLTIVWmKRGSGVVLSNE----NLLTLKSVRQEDAGKYVC 368
Cdd:cd05754     7 EPRSQEVRPGADVSFICrAKSKSPAYTLVW-TRVNGTLPSRAmdfnGILTIRNVQLSDAGTYVC 69

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172  403 GEKGQIKCFIRSTPPPdRIAWSWKETVLeSGTSGRYTVetvtTEEGVISTLTMSNIVPADfQTIYNCTAWNSFGSDTEII 482
Cdd:smart00410   9 GESVTLSCEASGSPPP-EVTWYKQGGKL-LAESGRFSV----SRSGSTSTLTISNVTPED-SGTYTCAATNSSGSASSGT 81

                   ...
gi 2105458172  483 RLK 485
Cdd:smart00410  82 TLT 84

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 306 RMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVWMKRGSGVVLSNENLLT---------LKSVRQEDAGKYvcrAVVPRVG 376
Cdd:cd05747     5 TILTKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQITsteykstfeISKVQMSDEGNY---TVVVENS 81

                          90
                  ....*....|
gi 2105458172 377 AGEKEVSLTV 386
Cdd:cd05747    82 EGKQEAQFTL 91

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2105458172 318 LGSDAVFNCAWTGNPSLTIVWMKRGSGVVLSNEN-------LLTLKSVRQEDAGKYVCRaVVPRVGA 377
Cdd:cd05856    18 VGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGenkkkkwTLSLKNLKPEDSGKYTCH-VSNRAGE 83

Immunoglobulin (Ig) domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig) domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 389 PPTISS-TQTQQALHGEKGQIKCFIRSTPPPdRIAWSWKETVLESGTSGRYTVETVTTEEGVISTLTMSNIVPADfQTIY 467
Cdd:cd05735     3 PAMITSyPNTTLATKGQKKEMSCTAHGEKPI-IVRWEKEDTIINPSEMSRYLVTTKEVGDEVISTLQILPTVRED-SGFF 80

                          90       100
                  ....*....|....*....|
gi 2105458172 468 NCTAWNSFGSDTEIIRLKEQ 487
Cdd:cd05735    81 SCHAINSYGEDRGIIQLTVQ 100

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 305 PRMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVW-MKRGSGV--------------VLSNENLLtLKSVRQEDAGKYVCR 369
Cdd:cd05734     2 PRFVVQPNDQDGIYGKAVVLNCSADGYPPPTIVWkHSKGSGVpqfqhivplngriqLLSNGSLL-IKHVLEEDSGYYLCK 80

                  .
gi 2105458172 370 A 370
Cdd:cd05734    81 V 81

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 305 PRMAAEPQSLQVDLGSDAVFNCAWTGNPSLTIVWmKRGSGV-------VLSNENL-------LTLKSVRQEDAGKYVCRA 370
Cdd:cd20954     2 PRWIVEPVDANVAAGQDVMLHCQADGFPTPTVTW-KKATGStpgeykdLLYDPNVrilpngtLVFGHVQKENEGHYLCEA 80

                          90
                  ....*....|....*..
gi 2105458172 371 vVPRVGAG-EKEVSLTV 386
Cdd:cd20954    81 -KNGIGSGlSKVIFLKV 96

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 389 PPTISST-QTQQALHGEKGQIKCFIRSTPPPdRIAWSWKETVLESGTSGRYTVETVTteegviSTLTMSNIVPADFQTiY 467
Cdd:pfam13927   1 KPVITVSpSSVTVREGETVTLTCEATGSPPP-TITWYKNGEPISSGSTRSRSLSGSN------STLTISNVTRSDAGT-Y 72

                  ....*.
gi 2105458172 468 NCTAWN 473
Cdd:pfam13927  73 TCVASN 78

Second immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and Necl-5), and similar domains; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and nectin-like protein 5 (Necl-5)) and similar proteins. Poliovirus (PV) binds to its cellular receptor (PVR/CD155) to initiate infection. CD155 is a membrane-anchored, single-span glycoprotein; its extracellular region has three Ig-like domains. There are four different isotypes of CD155 (referred to as alpha, beta, gamma, and delta), these result from alternate splicing of the CD155 mRNA, and have identical extracellular domains. CD155-beta and CD155-gamma are secreted, while CD155-alpha and CD155-delta are membrane-bound and function as PV receptors. The virus recognition site is contained in the amino-terminal domain, D1. Having the virus attachment site on the receptor distal from the plasma membrane may be important for successful initiation of infection of cells by the virus. CD155 binds in the poliovirus "canyon" and has a footprint similar to that of the intercellular adhesion molecule-1 receptor on human rhinoviruses. This group also includes the second Ig-like domain of nectin-1, also known as poliovirus receptor related protein(PVRL)1 or CD111.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 120 PVISGGPVvSLRAGDP-LNLTCHANNAKPAASIIWirNGEVlnGAMYSKTLLRDGRRESTV-STLHLSPSNIETGQHIIC 197
Cdd:cd05719     3 NSLEGGPA-LLIGGEPtLVATCISANGKPPASVTW--ETDL--KGEASTTQVRGSNGTVTVtSRYRLVPSREADGQPLTC 77

                          90
                  ....*....|....*....
gi 2105458172 198 KASNKAVPNGKETSVTIDI 216
Cdd:cd05719    78 VVEHPSLEKDQRISVTLNV 96

Second immunoglobulin (Ig)-like domain of nectin-like molcule-1 (Necl-1); member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin (Ig)-like domain of nectin-like molcule-1 (Necl-1; also known as cell adhesion molecule3 (CADM3)). These nectin-like molecules have similar domain structures to those of nectins. At least five nectin-like molecules have been identified (Necl-1 through Necl-5). These have an extracellular region containing three Ig-like domains, one transmembrane region, and one cytoplasmic region. The N-terminal Ig-like domain of the extracellular region belongs to the V-type subfamily of Ig domains is essential to cell-cell adhesion and plays a part in the interaction with the envelope glycoprotein D of various viruses. Necl-1 and Necl-2 have Ca(2+)-independent homophilic and heterophilic cell-cell adhesion activity. Necl-1 is specifically expressed in neural tissue and is important to the formation of synapses, axon bundles, and myelinated axons. Necl-2 is expressed in a wide variety of tissues and is a putative tumour suppressor gene which is downregulated in aggressive neuroblastoma. Ig domains are likely to participate in ligand binding and recognition.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 117 PEDPVISGGpVVSLRAGDPLNLTCHANNAKPAASIIWIRNGEVLNGAMYSktLLRDGRRES-TV-STLHLSPSNIETGQH 194
Cdd:cd07705     4 PQKPQITGY-ESAFKEKDKAKLRCTSSGSKPAANIKWRKGDQELEGAPTS--VQEDGNGKTfTVsSSVEFQVTREDDGAE 80

                          90       100
                  ....*....|....*....|...
gi 2105458172 195 IICKASNKAVPN-GKETSVTIDI 216
Cdd:cd07705    81 ITCSVGHESLHDsDRSTSQRIEV 103

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2105458172 224 LSVDPQPVLEGNLVKFHCSAKANPPVTlYRWAKGGSIIKEvSGD--TYEVTVDHS-FFTepvsCEVTNPLGSTnISRNVD 300
Cdd:pfam13895   4 LTPSPTVVTEGEPVTLTCSAPGNPPPS-YTWYKDGSAISS-SPNffTLSVSAEDSgTYT----CVARNGRGGK-VSNPVE 76

                  .
gi 2105458172 301 V 301
Cdd:pfam13895  77 L 77